How the firewall blocks the site?

A web firewall usually has a least of hundreds of bogus, and malicious URL or websites. If it comes across a website that is on the least than it will inform the PC user of the dangerous content before he or she actually visits it. Most firewalls in schools and business block sites by their content not by their name. this is how it works an administrator configures the firewall to block certain categories of websites. Some commonly blocked websites are audio and video sharing, proxy servers and ofcourse adult video. Firewalls are helpful when it comes to protecting your computer and the people who view it. But it is also sometimes bad. Firewalls sometimes block some sites like YouTube, sites like this one and gaming. The best method is knowing what your needs are and how to configure the firewall to let you do this. Firewalls slow down performance a little but its worth it.